Issue 68

F. E. Altunok et alii, Frattura ed Integrità Strutturale, 68 (2024) 280-295; DOI: 10.3221/IGF-ESIS.68.19

Figure 6: Geometrical and structural description of the specimen used in the validation study. In the referenced study, the performance of three adhesives—Araldite® AV138, Araldite® 2015, and SikaForce® 7752— was examined. The Cohesive Properties of these adhesives were detailed in Tab. 3, these properties were used to define material cards in Engineering Data module of ANSYS by computing the Separation-Distance Based Debonding properties according to the equations for the specific element used. The adherents of the joints are composed of Aluminum AA6082 T651, with the properties outlined in Tab. 4. Upon establishing the material data and geometric parameters, simulations were executed utilizing the ANSYS 2023 R2 Mechanical module. When generating the mesh, the primary focus in the simulations is directed towards refining the bonded region. Indeed, the influence of mesh size on other parts of the structure is relatively less important in the assessment of outcomes, considering that during tensile testing, the bonded area experiences a bending moment due to its asymmetric configuration. This phenomenon results in the concentration of tension at the boundaries of the bonded region, emphasizing the significance of the overlap zone and underscoring the need for a less detailed mesh elsewhere. To maintain consistency with the original study, the boundary conditions were set to ensure a true representation of a tensile test. Referring to Fig. 6, the specimens are fixed at one end, while a displacement of 1 mm in the positive "X" direction is applied to the opposite end. The mesh comprises hexahedral elements, where an element size of 2 mm is assigned to the overlapping region. The overall element size remains unchanged at its default setting. (Fig 7)

Property

Unit

Araldite® AV138

Araldite® 2015

SikaForce® 7752

4.9 േ 0.8 0.35 36.5 േ 2.5 39.5 േ 3.2 1.2 േ 0.1 1.6 േ 0.01 25.1 േ 0.3 30.2 േ 0.4 7.8 േ 0.7 0.20 േ 0.2 0.38 േ 0.2

1.9 േ 0.2 0.33 12.6 േ 0.6 21.6 േ 1.6 4.8 േ 0.8 0.6 േ 0.2 14.6 േ 1.3 17.9 േ 1.8 43.9 േ 3.4 0.4 േ 0.02 4.7 േ 0.3

0.5 േ 0.1 0.30 3.2 േ 0.5 11.5 േ 0.3 19.2 േ 1.4 0.2 േ 0.01 5.2 േ 1.1 10.2 േ 0.6 54.8 േ 6.4 2.4 േ 0.2 5.4 േ 0.5

Young’s modulus

GPa

Poisson’s ratio

-

Tensile yield stress

MPa

Tensile failure strength

MPa

Tensile failure strain

%

Shear modulus

GPa

Shear yield s tress

MPa

Shear failure strength

MPa

Shear failure strain

%

Toughness in tension

N/mm

Toughness in shear

N/mm

Table 3: Cohesive properties of the materials reported in [15].

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